The invention relates to a method and system for disconnecting an electrical machine from the drive axle of a vehicle such as a hybrid automotive vehicle while the vehicle is running. The method and system are particularly suited for a hybrid vehicle having a combustion engine in such manner as to make the electrical machine contribute to the traction of the vehicle.
Publication FR2723553, for instance, discloses an automotive vehicle having a selective command system for separate or simultaneous actuation of electrical and thermal power trains.
U.S. Pat. No. 5,403,244 discloses an electrical power train of a vehicle with direct transmission coupling and using a synchronization means based on friction plates similar to couplings with clutch plates. Clutch type couplings generate energy losses.
To increase efficiency, the known state of the technology is oriented toward dog type clutch couplings. In this regard, publication FR20905438 describes a control method employing two dog clutch couplers in which a force exerted on one of the dog clutch couplers, to bring it closer to the other dog clutch coupler, is modulated as a function of different approach phases.
The actual running of a vehicle makes it difficult to rapidly disengage a dog clutch without a shock occurring. This is so in all circumstances; i.e., regardless of whether the vehicle is running at a constant speed, or is accelerating or decelerating.